Revisiting the displacement current: Two key examples showing when and why it can be neglected

This work explores the role of the displacement current in systems beyond capacitors, focusing on coaxial cables and resistors with alternating currents. Although its contribution, compared to that of the conduction current, is negligible at low frequencies, the displacement current becomes essentia...

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Main Authors: Álvaro Suárez, Arturo C. Marti, Martín Monteiro
Format: Article
Language:Portuguese
Published: Sociedade Brasileira de Física 2025-08-01
Series:Revista Brasileira de Ensino de Física
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172025000100445&lng=en&tlng=en
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author Álvaro Suárez
Arturo C. Marti
Martín Monteiro
author_facet Álvaro Suárez
Arturo C. Marti
Martín Monteiro
author_sort Álvaro Suárez
collection DOAJ
description This work explores the role of the displacement current in systems beyond capacitors, focusing on coaxial cables and resistors with alternating currents. Although its contribution, compared to that of the conduction current, is negligible at low frequencies, the displacement current becomes essential for accurately describing electromagnetic fields in dynamic regimes. Introductory physics textbooks typically restrict the discussion of displacement currents to capacitor charging, which can limit the students’ understanding of its broader relevance and the interdependence of Maxwell’s equations. By analyzing two specific cases, we clarify the conditions under which the displacement current can be neglected, when simplified laws like Biot-Savart are valid, and where coupled electromagnetic equations are essential. This approach highlights the boundaries of common models and promotes a deeper understanding of dynamic field interactions.
format Article
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institution Kabale University
issn 1806-9126
language Portuguese
publishDate 2025-08-01
publisher Sociedade Brasileira de Física
record_format Article
series Revista Brasileira de Ensino de Física
spelling doaj-art-7729edbbc1934122a346b30172d942032025-08-20T03:45:07ZporSociedade Brasileira de FísicaRevista Brasileira de Ensino de Física1806-91262025-08-014710.1590/1806-9126-rbef-2025-0121Revisiting the displacement current: Two key examples showing when and why it can be neglectedÁlvaro Suárezhttps://orcid.org/0000-0002-5345-5565Arturo C. Martihttps://orcid.org/0000-0003-2023-8676Martín Monteirohttps://orcid.org/0000-0001-9472-2116This work explores the role of the displacement current in systems beyond capacitors, focusing on coaxial cables and resistors with alternating currents. Although its contribution, compared to that of the conduction current, is negligible at low frequencies, the displacement current becomes essential for accurately describing electromagnetic fields in dynamic regimes. Introductory physics textbooks typically restrict the discussion of displacement currents to capacitor charging, which can limit the students’ understanding of its broader relevance and the interdependence of Maxwell’s equations. By analyzing two specific cases, we clarify the conditions under which the displacement current can be neglected, when simplified laws like Biot-Savart are valid, and where coupled electromagnetic equations are essential. This approach highlights the boundaries of common models and promotes a deeper understanding of dynamic field interactions.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172025000100445&lng=en&tlng=enDisplacement currentMaxwell equationscoaxial cable
spellingShingle Álvaro Suárez
Arturo C. Marti
Martín Monteiro
Revisiting the displacement current: Two key examples showing when and why it can be neglected
Revista Brasileira de Ensino de Física
Displacement current
Maxwell equations
coaxial cable
title Revisiting the displacement current: Two key examples showing when and why it can be neglected
title_full Revisiting the displacement current: Two key examples showing when and why it can be neglected
title_fullStr Revisiting the displacement current: Two key examples showing when and why it can be neglected
title_full_unstemmed Revisiting the displacement current: Two key examples showing when and why it can be neglected
title_short Revisiting the displacement current: Two key examples showing when and why it can be neglected
title_sort revisiting the displacement current two key examples showing when and why it can be neglected
topic Displacement current
Maxwell equations
coaxial cable
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172025000100445&lng=en&tlng=en
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